This invention relates to an electrode clamping system or a sink-type or xe2x80x9csinkingxe2x80x9d electrical discharge machine (EDM) for machining parts.
EDM""s are used to machine or process a wide variety of parts or workpieces in a number of ways, such as by cutting, forging, injection molding engraving, and polishing, all involving the use of electrical discharges and a dielectric fluid. EDM""s of the sink-type, also known as xe2x80x9csinkingxe2x80x9d EDM""s have a sink or well, in which a workpiece to be processed is lowered while it is electrically connected to least one electrode. A dielectric fluid is injected into the electrodes during electrical discharge treatment of the workpiece, such that the dielectric fluid flushes the surface of the workpiece during treatment, in order to remove particles of the workpiece that are cut or machined from the surface of the workpiece during electrical discharge treatment and which would cause contamination of the surface of the workpiece, preventing further fine polishing of the surface if allowed to remain on the surface of the workpiece with the dielectric fluid containing the flushed-away contaminating particles then being collected in the sink.
Holders for clamping electrodes, which are attached to the workpiece during electrical discharge treatment of the workpiece, for sink type EDM""s, such as, for example, clamp model numbers 3R-6,51.13, and 3R-658.2E, together with model number 3R-651E-LS, both produced by 3R Company of Sweden, are known in the art, however they do not enable a dielectric fluid supply to flow through them to the electrodes.
Other holders, in which the clamping of electrodes is possible, such as, for example, clamp model number 3R-608,32, in combination with model number 311-601.3, both also produced by 3R Company of Sweden, enable the supply of a dielectric fluid to the electrode through an outer flexible flushing tube, such as model number 3R-103, which is attached to the holder, but does not lead through it. There, the flushing tube must be manually adjusted for every electrode in order to insure that the dielectric fluid flow is in the desired direction. Unfortunately, the flexible tube cannot always be properly positioned due to there being only limited space between the clamping system and the part being machined.
The electrode clamping system for a sink-type EDM according to the present invention includes an adjustable holder for clamping electrodes of different or adjustable sizes, and a dielectric fluid flow control system. The flow control system provides for lateral flushing of the workpiece with the dielectric fluid, which flows through the adjustable holder.
The construction of the electrode clamping system for a sink-type EDM according to the present invention includes the holder and the control circuit, wherein the holder enables simple clamping of the electrodes and the supply of the dielectric fluid into at least one nozzle, thereby allowing for direction and control of the dielectric fluid flow into a space or slot between the electrode and the workpiece being processed. The supply of the dielectric fluid to the sink-type EDM is enabled by positioning the holder on a head of the EDM and its automatic operation is enabled by mounting the clamping system on the machine head.
The system of the present invention successfully overcomes several technical problems that existed in the state of the art, including those of how to achieve the clamping of electrodes of different or adjustable sizes and how to supply the dielectric fluid for flushing away the contamination particles, produced by the EDM-sinking process, from the gap or slot that exists between the electrode and the workpiece, especially in the case of narrow and/or deep slots.